Technical Field
Aspects of this disclosure relate to a cleaning device and an image forming apparatus incorporating the cleaning device.
Related Art
Image forming apparatuses, such as printers, facsimile machines, and copiers, may include an electrostatic cleaning device as an intermediate-transfer-belt cleaning device to remove post-transfer residual toner on an intermediate transfer belt. Such an electrostatic cleaning device removes the toner from the intermediate transfer belt by action of electrostatic force.
The electrostatic cleaning device includes, for example, a cleaning brush roller to rotate while contacting the intermediate transfer belt as a cleaning target and a collection roller to rotate while contacting the cleaning brush roller. The cleaning brush roller and the collection roller are rotatably held in a casing. The cleaning brush roller is applied with a cleaning voltage, and the collection roller is applied with a collection voltage.
The post-transfer residual toner adhered on the surface of the intermediate transfer belt is electrostatically transferred from the surface of the intermediate transfer belt to the cleaning brush roller by the cleaning voltage and removed from the intermediate transfer belt. Toner electrostatically transferred to the cleaning brush roller is delivered with rotation of the cleaning brush roller to a contact position at which the cleaning brush roller contacts the collection roller, electrostatically transferred to the collection roller by the collection voltage, and collected from the cleaning brush roller to the collection roller.
However, when such a cleaning device is used for a long time of period, toner may re-adhere from the cleaning brush roller to the intermediate transfer belt. Such re-adhesion toner may pass through the cleaning device while remaining on the intermediate transfer belt and cause a stain-shaped abnormal image.